In my previous U.S. Pat. No. 3,902,744 a prefabricated metal chimney comprised of a plurality of double-walled chimney sections is disclosed wherein the inner wall members are joined together in such a way that a substantially air or smoke tight inner flue passage is provided throughout the chimney. In order to space the outer wall member properly from the inner wall member a series of circumferentially spaced apart spacer connectors were used at each end of each chimney section. Although the aforesaid arrangement proved satisfactory for overcoming the leakage problem of the inner pipe, a problem arose in certain installations with the individual spacer connectors. For many situations where unsymmetrical exterior loading was applied to the chimney, it was found that only one or two of the individual spacer connectors would take the entire load. This tended to cause a displacement of the inner relative to the outer pipe or, in some cases, a failure of the individual connector.
It is therefore one object of the present invention to solve the aforesaid problem and provide an improved prefabricated double-walled chimney section.
Another object of the invention is to provide an improved prefabricated double-walled metal chimney section that can be combined with like sections to form a chimney having a leak proof inner flue and wherein asymmetrical exterior loading will be transmitted substantially uniformly from the outer wall member to the inner wall member. Yet another object of the present invention is to provide a prefabricated double-walled metal chimney section that is particularly strong and durable when subjected to exterior loads and is also relatively easy to assemble in large scale production.